Page 1 of 13Schizophrenia Bulletin Opendoi:10.1093/schizbullopen/sgaa009© The Author(s) 2020. Published by Oxford University Press on behalf of the University of Maryland's school of medicine, Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.comReplication of Associations With Psychotic-Like Experiences in Middle Childhood From the Adolescent Brain Cognitive Development (ABCD) StudyNicole R. Karcher* ,1 , Rachel L. Loewy 2 , Mark Savill 2 , Shelli Avenevoli 3 , Rebekah S. Huber 4 , Tony J. Simon 5 , Ingrid N. Leckliter 5 , Kenneth J. Sher 6 , and Deanna M. Barch 1,7,1 Department of Psychiatry, Washington University School of Medicine, St. Louis, MO; 2 Department of Psychiatry, University of California, San Francisco, San Francisco, CA; 3 National Institute of Mental Health, Bethesda, MD; 4 Department of Psychiatry, University of Utah School of Medicine Salt Lake City, Salt Lake City, UT; 5 MIND Institute, University of California, Davis, Davis, CA; 6 Psychology Department, University of Missouri, Columbia, MO; 7 Department of Psychological and Brain Sciences, Washington University in St. Louis, St. Louis, MO*To whom correspondence should be addressed; Department of Psychiatry, Campus Box 1125, Washington University in St. Louis, One Brookings Drive, Saint Louis, MO 63110, US; tel: 314-935-8459, fax: 314-935-8790, e-mail: nkarcher@wustl.eduThe fi elds of psychology and psychiatry are increasingly recognizing the importance of replication efforts. The cur-rent study aimed to replicate previous fi ndings examining the construct validity and psychometric properties of a psychotic-like experiences (PLEs) measure in middle childhood using an independent subset of the baseline Adolescent Brain Cognitive Development (ABCD) sample. Using a remainder baseline sample of 7013 nine- to eleven-year-old children with complete data, we examined measurement invariance across race/ethnicity and sex, and examined the associations between the Prodromal Questionnaire Brief-Child Version (PQ-BC) and other measures of PLEs, internalizing symptoms, neuropsycho-logical test performance, and developmental milestones, to determine whether previously obtained results replicated in this nonoverlapping baseline sample subset. The results replicated measurement invariance across ethnicity and sex, and analyses again found higher PQ-BC scores for African American (β = .364, 95% CI = 0.292, 0.435) and Hispanic (β = .255, 95% CI = 0.185, 0.324) groups. We also replicated that higher PQ-BC scores were associ-ated with psychosis risk measures, higher rates of child-reported internalizing symptoms (Distress: β = .378, 95% CI = 0.357,0.398), neuropsychological test performance def i cits (eg, working memory; Distress: β = −.069, 95% CI = −0.096, −0.042), and motor (Distress: β = .026, 95% CI = 0.003, 0.049) and speech (Distress: β = .042, 95% CI = 0.018, 0.065) developmental milestone delays. The current results replicated many fi ndings from the orig-inal study examining the PQ-BC. We replicated evidence for mean differences in race/ethnicity, and associations with other PLE measures, greater internalizing symptoms, cog-nitive impairments, and developmental milestone delays. These fi ndings indicate robust and reliable associations be-tween PLEs and hypothesized correlates can be found in middle childhood nonclinical samples.Key words: psychotic-like experiences/replication/Adolescent Brain Cognitive Development/middle childhood/psychometric properties/construct validityIntroductionResearch is increasingly highlighting the importance of reproducibility in psychology and psychiatry. 1 These fi elds have been hit by what is sometimes coined the “replica-tion crisis,” with one investigation fi nding that only ~39% of included studies had fi ndings that replicate. 2 Part of the replication crisis is that many researchers are not al-ways engaging in robust research practices, 3,4 including replicating their own fi ndings. An analysis of the publica-tion history in the top 100 psychology journals between 1900 and 2012 found that only ~1.6% of all publications were replication attempts. 5 Thus, either attempting to rep-licate fi ndings is not currently standard practice, or these replication attempts are not being published. The current study aimed to replicate and extend results from our pre-viously published fi ndings 6 both to assess the robustness of those fi ndings and to support the act of replication as an important practice in the fi elds of psychology and psychiatry.Large datasets, such as the Adolescent Brain Cognitive Development (ABCD) Study, can be ideal for examining the reproducibility of fi ndings. The ABCD study is par-ticularly suited for this task since it fi rst released a subset of the baseline data (ie, Data Release 1.0.1, N = 4524;
